Touch detecting method and touch detecting device

Abstract

A touch detecting method includes determining a kind of a detected indicator based on a first area on a touch surface, obtaining a plurality of second capacitances formed by emphasizing a peak in comparison with a plurality of first capacitances by processing the plurality of first capacitances by a first filter in a case where the determining determines that the detected indicator is a stylus, deriving coordinates indicating a position of the stylus on the touch surface based on a second area on the touch surface, and deriving coordinates indicating a position of a finger on the touch surface based on a third area on the touch surface.

Description

BACKGROUNDTechnical Field[0001]The present disclosure relates to a touch detecting method and a touch detecting device.Description of the Related Art[0002]A capacitive type touch detecting device includes a touch sensor in which a plurality of X-electrodes each extending in a Y-direction and a plurality of Y-electrodes each extending in an X-direction are arranged so as to intersect each other. The touch detecting device is configured to repeat, for all of the Y-electrodes in order, processing of, for example, inputting a predetermined signal to a Y-electrode and extracting this signal from each X-electrode in order. When an indicator such as a finger, or a stylus approaches a touch surface, a capacitance occurs between the indicator and an X-electrode and a Y-electrode present in the vicinity of the indicator, and a part of a current flowing in the X-electrode through the capacitance is absorbed in the direction of the indicator. Thus, the amplitude of the signal extracted from the...

AI Technical Summary

Benefits of technology

The present patent aims to provide a method and device for detecting both fingers and stylus on a touch surface. The method involves determining the kind of indicator based on the first area on the touch surface, emphasizing a peak in a second area, and deriving the coordinates of the indicated position. This allows for accurate detection of both fingertip and stylus touches, providing a better user experience. The touch detecting device includes an analog to digital converter and a touch detecting circuit for this purpose.

Problems solved by technology

However, a technology described in the foregoing Patent Document 1 may not be able to detect the finger and the stylus suitably.

Then, a difference between coordinates indicating the center of gravity of the area and an original position indicated by the stylus is increased, so that it becomes difficult to detect the finger suitably.

Next, in the case of using the second threshold value lower than the first threshold value for the stylus, changes in capacitances due to approaching or touching of the touch surface by the stylus are very small, and it is therefore difficult, in the first place, to detect the position of the stylus accurately based on the threshold value determination on the capacitances.

Hence, it is difficult to detect the stylus suitably even when the second threshold value lower than the first threshold value is used.

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